Vacuum loading system

ABSTRACT

Apparatus and methods for providing granular material to a loading hopper preparatory to processing, provide an at least partially transparent receptacle for receiving material prior to processing machinery supplied by the hopper with the receptacle having a top, a valve for selectably connecting the receptacle to vacuum or to ambient air, vacuum drawn in the receptacle, a conduit connecting the receptacle to a supply of granular material, a valve selectably permitting material flow from the receptacle into the hopper and control temporally adjustably closing the first valve and opening the second valve responsively to visually detected presence of a suitable amount of material in the receptacle.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This patent application is based on and entitled to the benefit of thefiling date of provisional United States patent application 60/023,933,filed Aug. 9, 1996 in the name of Stephen B. Maguire and entitled"Vacuum Loading Apparatus and Method", pursuant to 35 USC 119 andspecifically claims the benefit of the filing date of such provisionalUnited States patent application, specifically Aug. 9, 1996, as theeffective filing date for the instant application.

BACKGROUND OF THE INVENTION--FIELD OF THE INVENTION

This invention relates to methods and apparatus for feeding granular andpowdery type materials to receptacles for storage of such materialsprior to processing the materials upon removal from the receptacles.Specifically, this invention relates to methods and apparatus forfeeding granular plastic resin materials and additives for granularplastic resin materials to receptacles for storage temporarily in thereceptacles prior to removal of the resin materials for processing byplastic molding and extrusion machinery.

BACKGROUND OF THE INVENTION--DESCRIPTION OF THE PRIOR ART

In the plastics industry automatic material conveying has been used formany years with vacuum being a common means for such conveying.

Blowers are sometimes used to provide positive pressure conveying. Inblower-driven systems, cyclone separators separate air from conveyedplastic resinous material prior to delivery to the material to a finaldelivery point.

However, vacuum is the preferred means for such conveying. Vacuumsystems tend to be cleaner, producing less dust than blower-driven,positive pressure systems.

As a part of a vacuum system it is known to provide a vacuum supply unitas an integral unit, with a vacuum source, the material receptacle andcontrols for the supply system all combined in a single package. Theseare inexpensive systems and are similar to conventional home vacuumcleaners and to vacuum cleaners sold under the registered trademark"Shop-Vac" to do-it-yourself home hobbyists. In the industrial contextsuch units may be mounted over a resinous material storage receptaclerequiring filling with resinous material. Such units sell for from$600.00 to $2,000.00 in the industrial context.

More sophisticated and better vacuum material loading systems arereferred to as "central" systems. Such central systems typically sellfor $2,000.00 or more per receptacle or station being loaded and cancontrol from 5 to 40 or more receptacles or loading stations.

In vacuum systems it is known to use cloth filters to filter plasticresinous material from air streams moving towards vacuum pumps. Thecloth filters typically become clogged rather quickly, requiringfrequent maintenance and replacement. Cloth filters also wear quicklyfrom granular plastics material impact and abrasion.

Existing devices use blow-back techniques to clear the filter betweenmaterial supply cycles. These blow back devices add cost and complexityto the system.

Some vacuum loading apparatus use wire screens to keep out largeparticles, thereby allowing small dust particles to move towards thevacuum pump. A large general filter can provide filtering for many orall of the receptacles at once.

It is known to use timers to time the loading of plastic resinousmaterial into receptacles or loading stations. Conventionally,individual timers are used for each loading station with the timersbeing preset in advance to control loading.

SUMMARY OF THE INVENTION

In one of its aspects this invention provides apparatus for providingplastic resinous or other granular or powdery material preferably to aplurality of receptacles for temporary storage of the plastic resinousor other granular or powdery material preparatory to processing of theplastic resinous or other granular or powdery material. In this aspectthe apparatus preferably includes a plurality of receptacles forreceiving the plastic resinous or other granular or powdery materialprior to processing thereof by plastics processing machinery, such asplastics extrusion machinery, gravimetric blenders, plastics compressionmolding machinery and/or plastics injection molding machinery or othermaterial processing machinery. The apparatus further preferably includesmeans for drawing vacuum in the receptacles.

Preferably, the apparatus is used in conjunction with one or more weighscale or gravimetric blenders, specifically to provide material feed toa receptacle associated with such blender for temporary storage prior tofurther processing. Alternatively, the apparatus may be used to supplymaterial directly to the input throat of plastics processing machineryor other machinery to which resinous, pelletized or even powderymaterial is supplied for processing.

The apparatus further preferably includes first valve means forselectably connecting associated temporary storage receptacles with thevacuum drawing means and conduit means for connecting the temporarystorage receptacles to one or more supplies of plastic resinousmaterial, or granular additive material such as coloring agents or othermaterial to be added to such resinous material prior to processing, orother powdery or granular materials to be fed and processed.

The apparatus further preferably includes second valve means forselectably permitting plastic resin material flow from the temporarymaterial storage receptacles for processing, and signal means foractuating the first and second valve means responsively to preselectedcriteria respecting optimal supply of the plastic resin material fromthe temporary material storage receptacles to plastics materialfabricating machines for processing.

The apparatus further preferably includes baffle means at an inlet tothe receptacles for directionally deflecting flow of plastic resinmaterial into the receptacle from the conduit thereby dissipatingkinetic energy of the plastic resin material.

In the invention at least one of the temporary material storagereceptacles may preferably have a top including means for selectablyconnecting the temporary material storage receptacle either to a vacuumline or to ambient air.

In the invention there may further be provided means for connecting theconduit to the temporary material storage receptacle including a plateinclined at an angle to the direction of material flow into thetemporary material storage receptacle for directionally deflectingmaterial entering the temporary material storage receptacle.

In another of its aspects the invention provides apparatus for providingplastic resinous or other granular material to a plurality of loadinghoppers, which may be material storage hoppers for weigh scale blenders,and for replenishing the material in the receptacles to preselectedmaterial levels preparatory to the delivery of the material therefromfor processing, where the apparatus includes signal control means foractuating first and second valve means responsively to preselectedcriteria respecting acceptable supply of the plastic resinous materialto individual hoppers associated with a weigh scale blender.

In another of its aspects the invention embraces baffle means within atleast one of the receptacles at the inlet from the conduit means forpreferably thrice directionally deflecting flow of airborne plasticresinous or other granular material drawn into the temporary materialstorage receptacle from the conduit thereby dissipating kinetic energyof the moving airborne resinous material.

In another aspect of the invention at least one of the temporarymaterial storage receptacles preferably has a one-piece top preferablyincluding means for selectably connecting the receptacle to the vacuumline or to ambient air and means for connecting the material supplyconduit to the temporary material storage receptacle including a plateinclined in an angle to the flow direction of material drawn into thereceptacle for downwardly deflecting horizontally flowing materialentering the temporary material storage receptacle.

In another of its aspects this invention provides a method for providingplastic resinous material to a temporary material storage receptacle andmaintaining the temporary material storage receptacle with a preselectedlevel of material prior to processing thereof by extrusion or moldingwhere the method includes drawing of vacuum within a temporary materialstorage receptacle associated with the hopper of a weigh scale blender,thereby inducing replenishing plastic resin material flow from thesupply into the into the temporary material storage receptacleassociated with a hopper portion of a weigh scale blender.

The vacuum conveying system apparatus aspect of the invention maintainsthe receptacles essentially continuously suitably full of granular,preferably plastic resin material by pulling the material from a remotelocation into the temporary material storage receptacle on an as-neededbasis. The process preferably cycles automatically, preferably using amaterial presence sensor. One vacuum pump and one control unitpreferably operate with as many temporary material storage receptaclesas necessary to keep many hoppers full.

A receptacle component in the apparatus aspect of the invention includesa vacuum line to the receptacle which is controlled by a valve actuatingwhen a vacuum is required in the receptacle. In one aspect of theinvention the valve controls a material inlet port and a clean-outaccess in a single, preferably aluminum, casting. The material lineconnected to the receptacle pulls granular, resinous or powdery materialunder the influence of vacuum from a remote material supply into thereceptacle.

A signal stops the loading of material into the receptacle and allowsmaterial to exit from the receptacle bottom. This signal may be producedby a material high level sensor or may preferably result from time-outof a preset timer.

The receptacle further includes an exit port which is closed duringreceptacle loading either by a flap closing by gravity and thereafterbeing held closed by the vacuum or more preferably by a valve that maybe operated by an air cylinder. Preferably, the valve is a slide gatevalve providing a vacuum seal for the receptacle.

In one of the aspects of the invention a blast deflection plate isprovided in the material air flow stream entering the receptacle. Themix of air and granular material enters the receptacle preferablyvertically from the top. However, the conveying line is preferablyhorizontal as it approaches the top of the receptacle. The conveyingline is preferably connected to a tube which is horizontal and whichguides the air-material mix towards a blast plate mounted at preferablyat a forty five degree angle, which deflects the material entrained inthe moving air-material mix downwardly into the receptacle from the top.

In another apparatus aspect of the invention the blast plate isremovable and replaceable. The blast plate is preferably steel;aluminum, from which the casting is preferably made, usually wears tooquickly. Removability of the blast plate also allows access if amaterial clog should occur in the vicinity of the blast plate.

A deceleration chamber is provided as a portion of the receptacle toslow the velocity of the air-material mix. This helps gravity separatethe material from the air.

With the invention, the air-material mix having the resinous or othergranular material entrained within the air is caused to move more slowlyafter entering the receptacle, to allow gravity to separate the materialfrom the air. The invention accomplishes this by providing a blastshield structure in position to be contacted by the incomingair/material mix. This shield is inside a deceleration chamberpreferably defined by a small box-like structure. This positioning ofthe blast shield within the deceleration chamber allows the air/materialmix to spread into a larger flow area, thus losing speed. The geometryis such that all of the material preferably goes through three flowdirection changes, bouncing off the chamber walls, with each changefurther dissipating energy stored in the moving material.

In a further aspect of the invention, an air cylinder operated vacuumvalve moves a disk from a position of sealing the vacuum source line toa position of sealing a conduit to atmosphere which is aligned with thevacuum source line, where the air cylinder operated valve is located atthe top of the receptacle. In one position the vacuum line is blockedbut a passage is open for atmospheric air to enter the receptaclethereby allowing the receptacle to empty. In another position thepassage to atmosphere is blocked and the vacuum line is connected to thereceptacle thereby permitting vacuum to be drawn in the receptacle andmaterial to be loaded into the receptacle by the vacuum system.

The casting at the top of the receptacle also desirably has a connectionfor the material supply line formed as an integral part of the casting.This material line preferably enters the casting horizontally. Incomingmaterial is preferably deflected downwardly into the receptacle via aplate desirably mounted at about a forty-five degree angle in thecasting. It is desirable to use a removable steel plate for addedresistance to wear and to allow access to the receptacle if somethingshould clog the flow path at the bend point.

The receptacle is desirably about an 8 inch diameter, about 14 inch longclear plastic polycarbonate tube, which allows the operator to watch thefilling action and to monitor operation of the system.

The vacuum sealing dump gate at the bottom of the receptacle ispreferably a slide gate incorporated into the preferably aluminumcasting forming the major portion of the bottom of the receptacle.Optionally, an o-ring may be provided for an improved vacuum seal;however an o-ring is not necessary. It may be desirable to provide ano-ring for processing very fine, powder-like materials.

The control portions of the apparatus and method aspects of theinvention permit loading each receptacle individually as a receptaclematerial sensor calls for material to be supplied thereto. When asensor, preferably in the receptacle or less preferably in a hopperbelow an associated receptacle, senses a low condition, the receptacleis queued to proceed with loading. To halt loading a simple time outcondition is preferably used.

In this aspect of the invention there is preferably provided a single"set timer" button on a controller. While any receptacle is beingloaded, the operator may press and hold the set timer button. So long asthe button is held, loading of that receptacle continues. When thebutton is released, loading stops and the shutoff time for thatreceptacle is reset to the new time determined according to the time thebutton was released. This resetting and time computation is preferablyperformed by a microprocessor which senses the shutoff time and storesthe relevant information in memory.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded side view, partially in section, of receptacleapparatus manifesting aspects of the invention.

FIG. 2 is a side elevation, partly in section, of receptacle apparatusmanifesting aspects of the invention with the receptacle apparatus shownin its assembled condition.

FIG. 3 is an elevation view of an assembled receptacle manifestingaspects of the invention taken looking from the right side in FIG. 2.

FIG. 4 is a top view of the casting forming a majority of the topportion of the receptacle illustrated in FIGS. 1 through 3.

FIG. 5 is a bottom view of the casting illustrated in FIG. 4.

FIG. 6 is a front view of the casting illustrated in FIG. 4.

FIG. 7 is a view of the casting illustrated in FIG. 4, looking from theright hand side in FIGS. 4 and 6.

FIG. 8 is a broken sectional view of a portion of the castingillustrated in FIGS. 4 through 7 taken at lines and arrows 8--8 in FIG.4.

FIG. 9 is a broken prospective view of a portion of the castingillustrated in FIGS. 4 through 8 taken in the direction of lines andarrows 9--9 in FIG. 8.

FIG. 10 is a broken sectional view of the casting illustrated in FIGS.4-9 taken at lines and arrows 10--10 in FIG. 4.

FIG. 11 is a sectional view of the casting illustrated in FIGS. 4through 10 taken at lines and arrows 11--11 in FIG. 4.

FIG. 12 is a sectional view of the casting illustrated in FIGS. 4through 11 taken at lines and arrows 12--12 in FIG. 6.

FIG. 13 is a view of the bottom plate portion of the casting formingsubstantially the bottom of the receptacle illustrated in FIG. 1 lookingdownwardly in FIGS. 1, 2 and 3.

FIG. 14 is a sectional view of the casting illustrated in FIG. 13 takenat lines and arrows 14--14 in FIG. 13.

FIG. 15 is a view of the bottom of the casting illustrated in FIGS. 13and 14 taken in the direction of lines and arrows 15--15 in FIG. 14.

FIG. 16 is a front view of the casting illustrated in FIGS. 13, 14 and15.

FIG. 17 is a schematic view of a power filter station manifestingaspects of the invention.

FIG. 18 is a side elevation of a power filter station manifestingaspects of the invention.

FIG. 19 is a front view of the power filter station illustrated in FIG.18.

FIG. 20 is a front view of a first linkage bar component of the powerfilter station illustrated in FIGS. 18 and 19.

FIG. 21 is a top view of the linkage bar illustrated in FIG. 20.

FIG. 22 is front view of a second linkage bar component of the powerfilter station illustrated generally in FIGS. 18 and 19.

FIG. 23 is a top view of two of the second linkage bars of FIG. 22 and across-bar joined together forming a component of the power filterstation illustrated generally in FIGS. 18 and 19.

FIG. 24 is a top view of a baffle illustrated in FIG. 1.

FIG. 25 is a front view of the baffle illustrated in FIG. 24.

FIG. 26 is a top view of a baffle enclosure illustrated in FIG. 1

FIG. 27 is a front view of a baffle enclosure illustrated in FIG. 26.

FIG. 28 is an exploded side view of a disk portion of a valve memberillustrated in FIG. 1.

FIG. 29 is a side view of the disk illustrated in FIG. 28.

FIG. 30 is a schematic view of a vacuum loading system manifestingaspects of the invention being used to supply granular material to twogravimetric blenders which in turn supply such granular material torespective plastic molding machines.

FIG. 31 is a schematic sectional view of a filter manifesting aspects ofthe invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS AND BEST MODE KNOWN FORPRACTICING THE INVENTION

Referring to the drawings in general and to FIG. 30 in particular, avacuum loading system in accordance with the preferred embodiment of theinvention is designated generally 10 and is used to provide granularmaterial to two or more devices requiring such granular material. In theembodiment illustrated in FIG. 30, the devices requiring such granularmaterial are a pair of gravimetric blenders each designated 12. Thegravimetric blenders are preferably mounted on molding machinesdesignated generally 14, which are preferably of the injection moldingtype. Each gravimetric blender 12 includes a hopper 16, which ispreferably divided internally into compartments being supplied withgranular material.

Vacuum loading system 10 includes at least one receptacle designatedgenerally 100. A plurality of such receptacles 100 are illustrated inFIG. 30. Each receptacle 100 is preferably mounted on top of hopper 16and is in communication with one of the internal compartments of hopper16.

The vacuum loading system supplies granular material from individualgranular material storage drums, which have been designated generally 18in FIG. 30, by drawing granular material as required from storage drums18 via lances 20, which are preferably in the form of hollow tubes.Flexible material supply hoses 24 are connected individually to ends oflances 20 and provide granular material drawn from individual storagedrums 18 to associated receptacles 100 to which individual materialsupply hoses 24 are connected as illustrated in FIG. 30. For purposes ofclarity respecting FIG. 30, one of the material storage drums 18, one ofthe lances 20, one of the material supply hoses 24 and one of thereceivers 100 have been numbered with the letter "A" following theindicator numeral to identify these as being connected together tosupply granular material from storage drum 18A to a particular internalcompartment within a hopper 16 of a gravimetric blender 12.

Vacuum loading system 10 as illustrated schematically in FIG. 30 furtherincludes a power filter station designated generally 204 which serves todraw a vacuum via a hose 26, in a manifold designated generally 22.Manifold 22 is connected to receptacles 100 via vacuum lines 40.

Gravimetric blenders 12 illustrated schematically in FIG. 30 arepreferably of the type available from Maguire Products, Inc. in Media,Pa.

Manifold 22 is preferably one and one-half inch outside diameteraluminum tubing. Vacuum hose 26 is preferably one and one-half inchinside diameter flexible hose material, as are material supply hoses 24Aand vacuum lines 40. The one and one-half inch inside diameter formaterial hoses 24 and vacuum lines 40 works well where a one horsepowerblower is provided as a part of power filter station 204 to draw avacuum via vacuum hose 26. The one and one-half inch inside diameter forthe material and vacuum hoses is suitable when a one horsepower bloweris used to draw the vacuum and lengths of material supply hoses 24 arein the neighborhood of twelve feet, for connection with lances 20inserted into granular material storage drums 18 to receptacles 100,where the length of vacuum lines 40 from receptacles 100 to manifold 22is on the order of five feet and where the length of vacuum hose 26 frommanifold 22 to power filter station 204 is on the order of twelve feet.

When a 2 and 1/2 horsepower or even a five horsepower blower is used atpower filter station 204 to draw a vacuum, it is desirable that vacuumhose 26 be on the order of two inches diameter.

While the vacuum loading system manifesting the invention is illustratedin FIG. 30 has been shown with four receptacles 100 providing granularmaterial from four storage drums 18 to four receptacles 100 associatedwith gravimetric blenders 12, larger or smaller numbers of receptaclesmay be accommodated according to the particular electronics utilized tocontrol the system and according to the size of the motor drawing thevacuum at power filter station 204.

Referring to FIGS. 1 through 3 in particular, a receptacle manifestingaspects of the invention is designated generally 100. Receptacle 100 ispreferably of generally cylindrical form and includes a cylindrical sidewall designated generally 104, a top designated generally 106 and abottom designated generally 108 in FIGS. 1, 2 and 3.

Top 106 is preferably formed substantially by a single, preferablyaluminum, casting which is illustrated in greater detail in FIGS. 4through 11. The casting substantially forming top 106 is designatedgenerally 132 in the drawings.

Referring to the drawings of casting 132, specifically FIGS. 4 through12, casting 132 is generally circular in shape and includes aair/material inlet connection designated generally 134 and an vacuumconnection designated generally 136.

Formed within air/material inlet connection 134 is a air/material flowpassageway designated generally 138 which is generally circular and ishorizontally disposed at the end thereof remote from receptacle 100. Theend of air/material inlet connection 134 and air/material flowpassageway 138 remote from receptacle 100 is designated generally 140 inthe drawings and is referred to hereinafter sometimes as a first end 140of air/material flow passageway 138.

The horizontal portion of air/material flow passageway 138 is designatedgenerally 142 and extends to a point of termination defined by adeflection member 144 which may be formed integrally as a portion ofcasting 132 but is more preferably provided as a plate secured in placeby suitable bolts engaging tapped holes in casting 132. Deflectionmember is preferably a steel plate, providing additional hardness overthe preferable aluminum of which casting 132 is cast. Providingdeflection member 144 as a bolted-in-place steel plate facilitatesremoval and replacement of member 144 when required due to wear or inthe event a clog develops in air/material flow passageway 138.

A vertically extending portion of air/material flow passageway 138 isdesignated generally 148, extends downwardly from deflection member 144into the cylindrical interior of receptacle 100 and opens specificallyinto the interior of a baffle enclosure which is designated generally150 in the drawings and which has resident therewithin a baffledesignated generally 152.

Baffle 152 illustrated in more detail in FIGS. 24 and 25 is generally"cross" shaped and includes a base portion 256 of the general crossshape and a pair of upstanding mounting ears 258. Baffle 152 fits withinbaffle enclosure 150 which is preferably fabricated of sheet metal andis of generally rectangular solid configuration in appearance. Baffleenclosure 150 has a generally rectangular top 266 which includes a largeaperture 260 for communication between the interior of baffle enclosure150 and the unnumbered outlet of vertical portion 148 of air/materialflow passageway 138. The two smaller, unnumbered apertures in top 266 ofbaffle enclosure 150, illustrated in FIG. 26, are provided to facilitatesecuring baffle enclosure 150 and baffle 152 contained therewithin inplace, preferably using suitable bolts entering tapped holes in casting136. These holes have not been shown in the drawings to facilitatedrawing clarity.

Baffle enclosure 150 further includes sides 262, which preferably extendgenerally perpendicularly from top 266, and canted bottom lips 264 whichare effectively inwardly inclined extensions of bottom portions of sides262. Lips 264 preferably extend inwardly at approximately a forty-fivedegree angle as illustrated in FIG. 27 and are relatively short inlength respecting the vertical height of sides 262, as also illustratedin FIG. 27 and as depicted in dotted lines in FIG. 26.

Baffle 152 fits within baffle enclosure with nut and bolt combinationspreferably being used to secure baffle 152 and baffle enclosure 150together. The holes illustrated in ears 258 of baffle 152, as shown inFIG. 25, align with the holes in walls 262 of baffle enclosure 150, asillustrated in FIG. 27, to permit securement of baffle 152 in placewithin baffle enclosure 150 by nut and bolt combinations.

When baffle 152 is secured in place within enclosure 150, base or crossportion of baffle 152 fits within or is inboard of canted bottom lips264 of enclosure 150. Hence, entrained granular plastic resinousmaterial pellets entering baffle enclosure 150 via aperture 260 aremoving in a vertically downward direction and encounter base portion 256of baffle 152. As the pellets hit base portion 256 of baffle 152, thepellets lose some of their kinetic energy and bounce randomly, with anupward component of motion and contact either the interior of sides 262or top 266 of baffle enclosure 150. Such contact causes the granularplastic resinous material pellets to lose further kinetic energy and tofall downwardly.

As these pellets fall downwardly they pass through space separatingedges of base portion 256 and the interior surfaces of sides 262 and,upon falling further, contact the upwardly and inwardly facing surfacesof canted bottom lips 264 and then fall out of baffle enclosure 150essentially due to their own weight.

Pellets that fall downwardly and come to rest on base portion 256 arejostled therefrom by additional pellets entering the baffle enclosure;these previously resting pellets migrate to the edge of cross portion256 and fall over the edge, contacting the inner surface of bottom lips264 and then fall into receptacle 100.

Hence, granular plastic resinous material pellets entrained in airentering receptacle 100 via air/material flow passageway 138 have theirvelocity changed (and kinetic energy reduced) once by encounter withdeflection member 144, which changes the direction of travel of thepellets by ninety degrees, have their direction of flow changed (andtheir kinetic energy reduced) a second time by encounter with baseportion 256 of baffle 150 and have their direction of flow of travelchanged (and their kinetic energy reduced) a third time by contact withcanted bottom lips 264, and possibly with sides 262 of baffle enclosure150, before entering the interior of receptacle 100. This "triple"contact, with three different solid surfaces, serves to reduce thekinetic energy of the entering granular plastic resinous materialpellets preferably to essentially zero.

Casting 132 further includes a vacuum passageway designated generally154 which extends generally horizontally from a valve member 156 to anorifice defined by vacuum connection 136 at a radially outward extremityof casting 132. Vacuum passageway 154 is generally preferably circularin cross-section and of relatively constant diameter from valve member156 to the outlet end defined by vacuum connection 136.

In the portion of vacuum passageway 154 within which valve member 156resides, which portion has been designated 158 in the drawings and isreferred to herein as a central portion of vacuum passageway 154, thepassageway is of larger diameter and includes a downwardly facingopening 160 communicating with the interior of receptacle 100. Furthercommunicating with vacuum passageway 154 and specifically with centralportion 158 is an air inlet passageway 162, which is best shown in FIGS.4 and 10 as well as in FIG. 6. Air inlet passageway 162 communicateswith ambient air via an orifice shown in FIG. 6 and designated 164;alternatively, air communication between air inlet passageway 162 andambient air may be facilitated by passage of air around a shaft 166 of afirst pneumatic piston-cylinder combination designated generally 168.The pneumatic piston-cylinder combination 168 is preferably fixed inposition on casting 132 and actuates valve member 156.

As best illustrated in the exploded view of FIG. 1, piston-cylindercombination 168 preferably has valve member 156 mounted on shaft 166where valve member 156 preferably includes a movable, reciprocal diskassembly designated generally 170.

Disk assembly 170 preferably includes a central metal disk 172preferably sandwiched between a pair of rubber seating gaskets, ofsubstantially the same diameter as metal disk 172, where the gaskets aredesignated 174 and are preferably held in place about disk 172 on shaft166 by lock nuts 176 which are separated from gaskets 174 by washers178, all as illustrated in the exploded view of FIG. 28 and in FIG. 29.

Piston-cylinder combination 168 preferably moves valve member 156between two positions. At one position valve member 156, specificallydisk assembly 170 which is illustrated at the left-most extremity of itstravel in FIGS. 1 and 2, is in abutting contact with a first annularvalve seat 180 defined by the interior portion of casting 132 wherevacuum passageway 154 enlarges to embrace central portion 158. At thisposition vacuum passageway 154 is open by virtue of the position of disk170 in FIGS. 1 and 2.

When disk 170 is moved to the right-most extremity of its travel, airinlet passageway 162 is open due to disk 170 in FIGS. 1 and 2 beingspaced away from a second annular valve seat 182 defined by juncture ofair inlet passageway 162 with central portion 158 of vacuum passageway154. At this position of valve member 156, ambient pressure existswithin receptacle 100 due to communication of the interior of receptacle100 with ambient air preferably via air inlet passageway 162. Passageway162 is best illustrated in the drawing figures depicting casting 132forming top 106 of receptacle 100; these are drawing FIGS. 4 through 12,as well as FIGS. 1 and 2.

When pneumatic piston-cylinder combination 168 is actuated to move valvemember 156 to the left in FIGS. 1 and 2, disk 170 moves against secondannular valve seat 182 thereby preventing communication between theinterior of receptacle 100 and ambient via air inlet passageway 162. Atthat position, disk 170 in FIG. 2 is removed from first annular valveseat 180, thereby permitting vacuum drawn through vacuum passageway 154to create vacuum within the interior of receptacle 100. Hence, pneumaticpiston-cylinder combination 168 operates valve member 156 to move disk170 from a position of sealing off the vacuum source line from theinterior of receptacle 100 to a position of sealing off an opening toatmosphere and hence sealing the interior of receptacle 100 fromambient.

When disk 170 is in position blocking vacuum passageway 154 butpassageway 162 is open for atmospheric air to enter receptacle 100, thisallows rapid emptying of receptacle 100 when material temporarily storedtherein is evacuated through the bottom of receptacle 100. When disk 170is at its alternate position the air passageway 162 to atmosphere isblocked and the vacuum line defined by vacuum passageway 154communicates with the receptacle interior.

Casting 132 preferably includes a circumfrential groove 184 formed in adownwardly facing surface of casting 132, into which fits preferablycylindrical side wall 104 of receptacle 100. Cylindrical side wall 104is preferably clear plastic tubing, preferably polycarbonate, and ispreferably about 8 inches in diameter and preferably about 14 inches inlength. Annular gaskets 186 may be provided around the upper and loweredges of cylindrical side wall 104 to facilitate sealing the upper edgeof cylindrical side wall 104 in cylindrical groove 184 of casting 132and sealing the lower edge of cylindrical side wall 104 in acorresponding annular groove 188 formed in bottom 108 of receptacle 100.

The assembly defining receptacle 100 is preferably secured together bytie rods 190 which are preferably secured in suitable apertures formedin casting 132 and in bottom 108; one such tie rod 190 is illustrated inFIG. 2. The tie rods urge casting 132 and bottom 108 towards oneanother.

Top 106 further include an access port 192 provided as a bore in casting132. Access port 192 illustrated in FIGS. 4 and 5 is preferably closedby a removable plug 194 illustrated in FIG. 1.

Plug 194 preferably includes a gasket to provide an air-tight seal ataccess port 192 during operation of receptacle 100 and the vacuumloading system. The access port permits access to the interior ofreceptacle 100 in the event of a material clog during operation.

Bottom 108 of receptacle 100 is preferably formed substantially by acasting 196 shown in section in FIGS. 1 and 2 and further preferablyincludes a slide gate, designated generally 198 in FIGS. 1 and 2, whichis preferably controlled by a second preferably pneumaticpiston-cylinder combination 200. Casting 196 is preferably generallycircular or cylindrical in configuration and preferably includes adownwardly sloping pan portion 202. The slope of pan portion 202 insuresthat granular material within receptacle 100 rests on slide gate 198.This is desirable in order so that granular material flows downwardlyout of receptacle 100 upon actuation of second pneumatic piston-cylindercombination 200 opening slide gate 198. Slide gate 198 may be equippedwith an o-ring for an improved vacuum seal, if necessary. Casting 196 ispreferably aluminum.

During normal operation slide gate 198 at the bottom of receptacle 100is normally open and closes only to enable vacuum to be drawn inreceptacle 100. When the timer associated with the microprocessor timesout and actuates valve member 156 moving disk 170 to simultaneouslybreak communication between the interior of receptacle 100 and vacuumpassageway 154 and allow communication between the interior ofreceptacle 100 and ambient air, slide gate 198 is opened essentiallysimultaneously by the microprocessor actuating pneumatic piston-cylindercombination 200.

A capacitive type material sensor 42 is preferably provided in asuitable aperture formed in casting 196 at the position illustrated inFIG. 1. Capacitive material sensor 42 when provided at this positionprovides an accurate gauge of the presence or absence of the requiredgranular material being within receptacle 100. Alternatively, acapacitive material sensor may be provided within the preferablytransparent polycarbonate wall 104 of receptacle 100. However,positioning capacitive material sensor 42 as illustrated in FIG. 1,secured within an orifice or aperture within casting 196, is preferred.

A power filter station is illustrated schematically in FIG. 17 and inmore detail in FIGS. 18 and 19.

In FIG. 17 where the power filter station is shown in schematic form,the station is designated generally 204 and is preferably constructedutilizing a preferably steel frame designated 206 which preferablyincludes four steel uprights 208, a steel base member 210 and a plate,which is preferably steel, affixed to the upper extremities of uprights208 and designated 212, which serves to support the electronic controlsfor the vacuum loading system where those controls are designatedgenerally 214 in FIGS. 18 and 19.

Power filter station 204 includes an air inlet conduit 216 and afiltered air outlet conduit 218, both of which are affixed to plate 212,preferably by welding, and are aligned with apertures of sizecorresponding to the interiors of conduits 216, 218 for flow ofunfiltered air and filtered air respectively into and out of powerfilter station 204.

Connected to plate 212 and extending away therefrom initially atsubstantially a right angle and then closer to parallel with plate 212is a deflector plate 220 positioned so that air entering the filterthrough conduit 216 encounters deflector plate 220. As a result airentering the filter is forced to change direction and lose some of itskinetic energy due to encounter with deflector plate 220.

There is further provided about the aperture in plate 212 communicatingwith filtered air outlet conduit 218 a preferably wire frame 222 aboutwhich a filter bag 224 is mounted with wire frame 222 serving to preventthe collapse of filter bag 224 as air leaves the filter via conduit 218.

Conduits 216, 218 may be one and one-half inch outside diameter tubesabout which flexible plastic tubular sleeves may be fitted to connectconduits 216, 218 to other portions of the vacuum loading system. One ofthese tubular sleeves is designated 226 in FIG. 18 and is shown inposition over air inlet conduit 216.

There may further be included as a portion of power filter station 204 acollection receptacle 228 which may be a conventional five gallonplastic bucket which is preferably pressed to seal against plate 212. Agasket may be utilized at the area of contact between collectionreceptacle 228 and plate 212 to provide a substantially air tight seal.Collection receptacle 228 is preferably supported by and sits in a tray230 which is supported by two linkage bars 232, 234, with the longerlinkage bar denoted as a first linkage bar and designated 232 in thedrawings. The shorter linkage bar is referred to as a second linkage barand is designated 234 in the drawings. Connection between tray 230 andfirst and second linkage bars 232, 234 is by suitable pivotalconnections designated 236 in the drawings. First and second linkagebars 232, 234 are respectively secured to rear ones of uprights 208 withthese being designated 208_(R) in FIG. 18.

As illustrated in FIG. 18 there may be optionally provided a cylindricaltubular extension, designated 242 in FIGS. 18 and 19, between the upperlip of collection receptacle 228 (which is preferably an conventionalfive gallon pail as indicated above), and plate 212 supportingelectronic controls 214. A gasket member 244 may be provided betweenextension 242 and plate 212 and another gasket, not shown but denotedgenerally by the line between collection receptacle 228 and cylindricalextension 244, may further be provided to assure the vacuum-tight sealbetween cylindrical extension 242 and collection receptacle 228.

During operation of the vacuum loading system a blower, which isdesignated generally 246 and illustrated in FIGS. 18 and 19, driven byan appropriate motor is used to draw vacuum through line 248 whichpreferably exits from filter 224 via connection with filtered air outletconduit 218 as illustrated schematically in FIG. 17. Line 248 is hiddenfrom view in FIGS. 18 and 19 by conduit 216 and electronic controls 214respectively. Air is drawn into the power filter station via flexibleplastic tubing (or some other material) conduit 226 which is connectedto air inlet conduit 216 as illustrated in FIG. 18 and is also connectedto vacuum connection 136 and hence to vacuum passageway 154 of top 106of receptacle 100.

Air inlet conduit 216 may be connected to a plurality of vacuumpassageways 154 associated with the plurality of receptacles 100 viamanifold 22 or by various splitters. Hence, power filter station 204 mayserve a plurality of receptacles 100 as illustrated in FIG. 1, just asdo electronic controls 214 and the associated microprocessor.

Pivotal connections 236 of first and second linkage bars 232, 234 withrear upright 208_(R) are separated by a vertical distance which is thesame vertical distance by which pivotal connections 236 of first andsecond linkage bars 232, 234 are separated at the connection with tray230. This arrangement assures that as tray 230 is raised and lowered byrotation of first and second linkage bars about their points 236 ofpivotal connection with upright 208_(R), tray 230 remains level at alltimes since first and second linkage bars 232, 234 remain parallel oneto another.

The configuration of first linkage bars 232 is illustrated in FIGS. 22and 23. First linkage bar 232 preferably has an offset, which has notbeen numbered in the drawings, in each of the first linkage bars tofacilitate the bars fitting closely against vertical sides 231 of tray230. Vertical sides 231 are clearly shown in FIG. 18 and appear as darkvertical lines in FIG. 19. First linkage bar 232 preferably includes anear portion 233 separated from a main portion 250 by an unnumberedoffset portion. Main portions 250 of two first linkage bars 232 arepreferably connected by a rod 252 to which a handle is affixed tofacilitate raising and lowering of tray 230 on which collectionreceptacle 228 rests.

Second linkage bar 234 is illustrated in greater detail in FIGS. 20 and21 and similarly includes an ear portion 235 and a main portion 254where main and ear portions 235, 254 are separated by an unnumberedoffset portion similarly to first linkage bar 232.

When the vacuum loading system is used, typically a plurality ofreceptacles 100 are provided with each receptacle 100 being locatedabove a hopper or storage bin associated with a weigh scale blender orother plastics and/or granular material processing machinery asillustrated in FIG. 30. The receptacle 100 above the hopper of the weighscale blender may include a material level sensor 42. When the sensorsuch as sensor 42 senses that the material level is excessively low,below a preselected level, the sensor provides a signal sensed by amicroprocessor forming a part of the central system for the vacuumloading system. The microprocessor may be housed with other electroniccontrols 214 positioned on plate 212 supported by uprights 208 of apower filter station 204 illustrated in FIGS. 18, 19 and 30.

When the microprocessor receives a signal indicating that the materiallevel is low in a receptacle 100 and hopper associated with a materiallevel sensor 42 of interest, the microprocessor actuates secondpneumatic piston-cylinder combination 200 thereby closing slide gate198. (Granular material, which was within receptacle 100 has alreadyflown downwardly out of receptacle 100 through slide gate 198 into theassociated hopper. Downward material flow out of receptacle 100 into theassociated hopper has continued until receptacle 100 was empty.)

When receptacle 100 is empty valve member 156 (which had been positionedto permit ambient air flow into receptacle 100 to facilitate thedownward flow of material out of receptacle 100) is positioned bypneumatic piston-cylinder combination 168 moving disk 170 to the left inFIGS. 1 and 2 thereby sealing the interior of receptacle 100 fromambient air and facilitating communication between the interior ofreceptacle 100 and vacuum line 154. As vacuum is drawn from anassociated storage drum 18 via the associated lance 20 and supply hoses24 through line 154, a vacuum is created within the interior ofreceptacle 100 and an air-material mix is drawn through air-materialflow passageway 138.

The air-material mix initially encounters deflector member 144, whichresults in a change in direction of the air stream with the materialentrained therein, and then encounters baffle 152 within baffleenclosure 150. As the granular plastic material pellets contact baffle152, they lose additional kinetic energy over and above that lost due tocontact with deflector member 144 and fall to the bottom of receptacle100. The air which had been carrying the granular plastic resinousmaterial pellets is drawn out of receptacle 100 by vacuum drawn throughvacuum passageway 154.

This loading of receptacle 100 with granular plastic resinous materialpellets may continue until material sensor 42 provided in receptacle 100senses that an adequate level of granular plastic resinous materialpellets is within receptacle 100 whereupon a signal sent to themicroprocessor by the sensor in receptacle 100 causes the microprocessorto actuate first pneumatic piston-cylinder combination 168 therebymoving disk 170 to the right in FIGS. 1 and 2, breaking the vacuum inreceptacle 100 by causing the interior of receptacle 100 to communicatewith ambient air and sealing vacuum passageway 154 from the interior ofreceptacle 100. Once the vacuum is broken within the interior ofreceptacle 100, no additional material flows since there is no pressuredifferential to cause the air/material mix to flow from associatedgranular material storage drum 18 through lance 20, associated materialsupply hose 24 and through air/material flow passageway 138 intoreceptacle 100.

As the preferred method for regulating and stopping the flow of materialand particularly the entrained granular plastic resinous materialpellets in the air stream into receptacle 100, the microprocessorcontroller preferably includes a timer. The timer has a preset timeprogrammed therein for each receptacle 100 of interest and begins totime out when the microprocessor actuates first pneumaticpiston-cylinder combination 168 of a receptacle 100 of interest, movingvalve member 156 and particularly disk 170 to the left in FIGS. 1 and 2,thereby permitting vacuum to be drawn in receptacle 100 by vacuum invacuum passageway 154, causing granular plastic resinous materialpellets entrained in the air stream to enter receptacle 100 travel fromassociated granular material storage drum 18 through associated lance20, associated supply hose 24 via air/material passageway 138.

When the timer associated with the microprocessor times out respectingthe time for the receptacle 100 of interest, indicating that the desiredlevel of granular plastic resinous material pellets is within receptacle100, the microprocessor actuates first pneumatic piston-cylindercombination 168, moving valve member 156 and disk 170 to the right inFIGS. 1 and 2. This seals off vacuum passageway 154 from the interior ofreceptacle 100 and opens air inlet passageway 162, thereby providingcommunication between the interior of receptacle 100 and ambient air,thus stopping flow of granular plastic resinous material pelletsentrained in the airstream moving through passageway 138 into theinterior of receptacle 100.

Hence, when a signal is received from a material level sensor indicatingthat a hopper associated with a given receptacle requires additionalmaterial, slide gate 198, which had been open, is closed by themicroprocessor actuating second pneumatic piston-cylinder combination200. Preferably substantially simultaneously the microprocessor actuatesfirst pneumatic piston-cylinder combination 168, moving valve member 156to the left in FIGS. 1 and 2 thereby establishing vacuum communicationbetween vacuum passageway 154 and the interior of receptacle 100,permitting vacuum to draw granular plastic resinous material pelletsentrained in air into the interior of receptacle 100 from granularmaterial storage drum 18 via lance 20 and material supply hose 24connecting with air/material passageway 138.

As these operations occur the timer commences timing for thatreceptacle. Valve member 156 for the receptacle 100 of interest ismaintained at its position, to the left in FIGS. 1 and 2, until thetimer times out for the receptacle 100 of interest. Once the timer timesout, the microprocessor actuates first pneumatic-piston cylindercombination 168 associated with the receptacle 100 of interest therebymoving valve member 156 associated with the receptacle 100 of interestto the right in FIG. 2, breaking the vacuum in receptacle 100 by openingair inlet passageway 162 to the interior of receptacle 100 therebyhalting flow of granular plastic resinous material pellets entrained inair into the interior of receptacle 100; the microprocessor also opensslide gate 198 by actuating second piston-cylinder combination 200thereby permitting the preselected amount of granular plastic resinousmaterial pellets to flow downwardly out of receptacle 100 through slidegate 198 and into the hopper requiring this material. Such operationcontinues, cyclicly, until the associated hopper and the level sensortherein indicates that additional material is no longer required. Themicroprocessor preferably cycles continuously among all of receptacles100 forming a part of a given system such as illustrated in FIG. 30 andaccepts signals from material level sensors in receptacles 100 of thevacuum loading system.

Preferably, the level sensor is located in the receptacle 100 and themicroprocessor programmed to provide material from receptacle 100 byactuating second pneumatic piston-cylinder combination 200 therebyopening slide gate 198 only when material is required by the receptaclehopper combination; the microprocessor effectuates filling of receptacle100 by actuating first pneumatic piston-cylinder combination and movingvalve member 156 to permit vacuum to be drawn in the interior ofreceptacle 100 whenever material sensor 42 within receptacle 100indicates material is required.

The timing for a particular receptacle being loaded may be adjusted byan operator actuating a set timer button associated with the controllerand microprocessor. A set timer button is illustrated schematically as apart of electronic controls 214 in FIG. 19 and is designated generally240.

While any receptacle is being loaded, an attending operator may pressand hold the set timer button. As long as the set time button ispressed, loading of the receptacle continues. When the operator releasesthe button, this signals the microprocessor to stop loading granularplastic resinous material into the receptacle which had been the subjectof the loading operation and to reset the timing associated with thatparticular receptacle to a new time, which is defined as the timeelapsed from commencement of loading of the associated receptacle untilthe operator released the set timer button. This arrangement permits anoperator to watch the level of material rise in a receptacle 100, sincecylindrical wall 104 is clear, and further permits the operator to stopthe material flow into receptacle 100 when exactly the desired level ofgranular plastic resinous material pellets or other granular material isreached in receptacle 100. No trial and error is involved; oneobservation of the material flowing into a given receptacle 100 andactuation of the set timer button is all that is required.

The microprocessor portion of electronic controls 214 sequences seriallyamong all of the receptacles 100 defining loading stations and actuatesthe pneumatic piston-cylinder combination 168 to load a given receptacle100 upon sensing that receptacle 100 may require material, since ahopper located below and associated with a given receptacle 100 requiresmaterial from receptacle 100 via slide gate 198.

Individual loading of receptacles 100 and the push button-actuatedupdating of the loading time of individual receptacles 100, based onrelease of the set timer button by an operator, permits immediateadjustment of loading time of receptacles 100 as needed. Loading time ofreceptacles 100 can vary according to the particular material beingloaded into a receptacle 100, the size of the feed line used to supplythe material entrained in the air stream to receptacle 100, the distancea particular receptacle 100 is from the main supply of material, thehorsepower of the blower being used to create the vacuum, and othervariable environmental conditions; all of these can effect the time forloading of the desired material into receptacle 100. Adjustment of theloading times for the receptacles 100 is extremely easy since anoperator need only observe the loading of a receptacle one time andpress the button when the material reaches the desired level. With thissystem, each receptacle may have its own unique loading time, which canbe easily and independently varied without respect to other receptaclesforming a part of the system.

In accordance with the foregoing, a large number of receptacles can beutilized in a single vacuum loading system controlled by amicroprocessor with only minimal attendance required by a humanoperator.

FIG. 31 illustrates a preferred embodiment of a vacuum filter unitportion of the vacuum loading system of the invention where the vacuumfilter unit includes a conventional bucket 28 which rests upon a shelf,such as indicated generally 230 in FIG. 18 and is moveable vertically byoperation of first and second linkage bars 232, 234 pivoting aboutpivotal connections 236, all as illustrated in FIG. 18.

In the operating position, first and second linkage bars 232, 234 haverotated counter-clockwise, when considering FIG. 18, about pivotalconnections 236 in response to spring bias of spring means, not shown,to urge bucket 28 upwardly against the downwardly facing surface ofplate 212 as illustrated in FIG. 31. An annular preferably soft, rubberurethane gasket 32 mounted either on the vertical lip of bucket 28 orthe lower surface of plate 212, provides an air-tight seal for vacuum tobe drawn within bucket 28.

A vacuum inlet connection conduit 44 extends through plate 212, asillustrated in FIG. 31. An upper or distal end of vacuum inletconnection conduit 44 is designated 46 in FIG. 31 and is remote fromplate 212 and bucket 28. Vacuum inlet connection conduit 44 is connectedat distal end 46 to vacuum hose 26 illustrated in FIG. 30 so that vacuummay be drawn through vacuum inlet connection conduit 44.

Fixedly connected to an aperture 48 in plate 212 is a vacuum outletconnection conduit 50. A deflector plate 52 is fixedly connected tovacuum outlet connection conduit 50 proximate the end thereof which isremote from plate 212. Deflector plate 52 is illustrated in section inFIG. 31 to enhance drawing clarity. Deflector plate 52 is preferablycircular and has a downwardly extending lip designated generally 54 inFIG. 31. Deflector plate 52 has an aperture formed therein so thatdeflector plate 52 may fit snugly about and be fixedly connected tovacuum outlet connection conduit 50 at the end thereof remote from plate212.

Attached to lip 54 is a filter bag 56 providing the actual air filteringfor the air drawn by vacuum into bucket 28 through vacuum inletconnection conduit 44.

Vacuum outlet connection conduit 50 exhausts through aperture 48 inplate 212 into plenumbox 38 which is fixedly connected to the upwardlyfacing surface of plate 212 as illustrated in FIG. 31.

Connected to plenumbox 38 is a vacuum drawing conduit 58 communicatingwith the interior of plenumbox 38. Vacuum drawing conduit 58 leads to avacuum pump so that vacuum may be drawn through vacuum drawing conduit58 and thereby from plenumbox 38, the interior of bucket 28, throughconduit 44, etc.

Mounted in one wall of plenumbox 38, preferably the top wall asillustrated in FIG. 31, is a blow-by valve 34 which is actuated by apneumatic piston cylinder combination schematically illustrated in FIG.31 and designated 36. When opened by action of pneumatic piston cylindercombination 36, blow-by valve 34 allows ambient air to enter plenumbox38 and be drawn through vacuum drawing conduit 58 by the vacuum pump,not illustrated in FIG. 31.

Desirably vacuum drawing conduit 58 and plenumbox 38 are fixedly securedtogether for example by welding and are fabricated of metal. Furtherdesirably, blow-by valve 34 and pneumatic piston cylinder combination 36actuating valve 34 are enclosed within a housing schematicallyillustrated in FIG. 31 and designated generally 60. Housing 60 ispreferably welded or otherwise fixedly connected to the exterior ofplenumbox 38 so that workers and others in the vicinity of the vacuumloading system cannot access blow-by valve 34 with their fingers.Similarly, a vacuum drawing conduit 58 is preferably sufficiently longthat an operator cannot insert fingers into the interior of plenumbox 38via vacuum drawing conduit 58. This is because the force supplied bypneumatic piston cylinder combination 36 to open or close blow-by valve34 can be very substantial and the action of blow-by valve 34 is withsufficient force to sever one's finger.

During operation of this system when the vacuum is preferably drawncontinuously by the vacuum pump running continuously and drawing vacuumthrough vacuum conduit 58. When material is being feed or drawn byvacuum into any one of receptacles 100, blow-by valve 34 is closed bypneumatic piston cylinder combination 36 so that vacuum may be drawnthroughout the system by the vacuum pump. In this condition, air beingdrawn as vacuum enters bucket 28 to be filtered via entry through vacuuminlet connection conduit 44 as indicated by arrow A in FIG. 31. Airdrawn through vacuum inlet connection conduit 44 by the action of thevacuum pump drawing a vacuum through vacuum drawing conduit 58encounters defector plate 52 and is deflected in a manner indicated byarrows B and C in FIG. 31. This action serves to slow the air beingdrawn as vacuum from the receptacle of interest by operation of thevacuum pump.

This air or vacuum drawn into bucket 28 through vacuum inlet connectionconduit 44 may have some particles of granular material thereindepending upon what has happened in the receptacle through which thevacuum is being drawn. Air of the vacuum drawn air being deflected byplate 52 as illustrated by arrows B and C, works to slow the vacuumdrawn air, spreading the vacuum drawn air and causing granular materialcarried by that air to collect in the bottom of bucket 28.

The vacuum drawn air is drawn by the vacuum through filter bag 56 goinginto an inlet of vacuum outlet connection conduit 50 as indicated byarrow D in FIG. 31. The vacuum drawn air exiting from vacuum outletconnection conduit 50 at aperture 48 is then drawn through plenumbox 38as indicated by arrow E in FIG. 31 into vacuum drawing conduit 58 asindicated by arrow F in FIG. 31 and travels to the vacuum pump where thevacuum drawn air is exhausted to atmosphere.

Whenever the vacuum drawing phase of operation of the system isconcluded and material is no longer being drawn into receptacles, vacuumis relieved by actuation of piston cylinder combination 36 openingblow-by valve 34 thereby letting air into plenumbox 38 whereupon thisinlet air may propagate throughout the system as indicated by dottedarrows G and H in FIG. 31. This contributes to extending the life of thevacuum pump so that the vacuum pump is not continually trying to drawn avacuum. If the pump continuously tries to draw a vacuum from a systemwhich would be closed, this would very much shorten the life of thevacuum pump would overheat and rapidly fail.

In addition to air being permitted to enter the system by operation ofblow-by valve 34, at the same time air is also permitted to enter thesystem at the top of the receptacles illustrated in FIGS. 1, 2, 4-12 and30 when the piston cylinder combination 168 moves disk assembly 170 tothe right, to the position illustrated in dotted lines in FIGS. 1 and 2.At this position, air is permitted to propagate by entering a givenreceptacle of interest through orifice 164 defining one end of inletpassage way 162 in casting 132 forming top 106 of a given receptacle100.

The vacuum filter apparatus illustrated in FIG. 31 may serve manyreceptacles 100 connected to a common manifold illustrated in FIG. 30.Use of the air and vacuum filter apparatus illustrated in FIG. 31 is notlimited to four receptacles as is illustrated in FIG. 30; the number ofreceptacles and associated equipment illustrated in FIG. 30 is by way ofexample only. Other numbers of components may be used together with asingle air-vacuum filter apparatus such as illustrated in FIG. 31.

When the air vacuum filter apparatus illustrated in FIG. 31 is used withmultiple receptacles 100, closure of the valve defined by disk 170 atthe upper portion of receptacle 100 to effectuate a vacuum in a givenreceptacle 100 is accompanied by closure by blow-by valve 34 illustratedin FIG. 1, no matter which one of receptacles 100 as being vacuum loadedwith granular material.

In the multiple station version of the vacuum loading system illustratedin FIG. 30, vacuum is drawn via vacuum hose "26" leading the vacuumconnection conduit 44 and in turn vacuum is drawn through manifold 22which serves all of the loading stations defined by receptacles 100,with loading of all such receptacles utilizing a single vacuum pump.

Valve 170 built into casting 132 forming top 106 of each receptacle 100is maintained in a default position at which vacuum is shut off and airis allowed to enter receptacle 100 until such time as material needs tobe vacuum loaded into receptacle 100. This default position of valve 170is illustrated at dotted lines in FIGS. 1 and 2.

When a given receptacle requires material as sensed by capacitive sensor42 mounted in casting 196 forming bottom 108 of receptacle 100, themicroprocessor portion of the control electronics for the vacuum loadingsystem senses that the material is needed at that receptacle 100 andoperates to close valve 170 at the top of receptacle 100 therebyallowing vacuum to be drawn in the interior receptacle 100 therebydrawing air with granular resinous material entrained therein from anassociated storage drum 18 through a lance 20 and through a materialsupply hose 24 into the interior receptacle 100. Vacuum is drawn for apreselected time as controlled by the microprocessor, which preselectedtime may be adjusted by the operator in the manner indicated elsewhereherein.

The electronic control for the vacuum loading system is preferablyprovided in a housing which may rest on the top of plate 212; theelectronic control system for the vacuum loading system is designatedgenerally as 214 in FIGS. 18 and 19.

As illustrated in FIG. 19, in schematic fashion, electronic control 214,which includes a microprocessor and is connected to the vacuum pump, theblow-by valve 34, all preferably capacitive material sensor 42 and allof the preferably pneumatic piston-cylinder combination may handle amultiple number of receptacles where facility to control eightreceptacles is illustrated in FIG. 19 as indicated by eight "on-off"buttons, one for each receptacle of interest. A single button 240 isprovided for an operator to reset fill time for each receptacle 100controlled by electronic control 214. The microprocessor portion ofelectronic control 214 sequences through receptacles 100 serially one ata time, so that the operator, if desiring to adjust the fill the timefor any given receptacle, merely waits for that receptacle to beactivated and for material to begin to flow into that receptacle. Oncethis occurs, the operator presses button 240 and continues to observethe material flowing into the receptacle 100 of interest. When thematerial level in receptacle 100 reaches the level the operator believesappropriate, the operator releases button 240. Such release of button240 sets a new stop point or stop time and hence sets a new elapsed timefor filling of a given receptacle 100. Button 240 does not regulate thetime at which a given receptacle starts to fill; button 240 regulatesshut off time. In that regard, it is an important feature of thisinvention to provide a transparent or at least translucent and in anyevent visible material level receptacle allowing an operator to observethat fill is proceeding respecting such receptacle and to regulate suchfill by depressing and then releasing button 240 to adjust shut off timefor fill of the receptacle 100 of interest.

Material loading conditions change due to changes in temperature,humidity, changes in material and the like. Typically, loading time foreach receptacle must be adjusted every day or two to maintain the vacuumloading system of the invention in the optimum mode for operation.

What is claimed is:
 1. Apparatus for providing granular material to aloading hopper preparatory to processing comprising:a. an at leastpartially transparent receptacle for receiving said material prior toprocessing thereof by machinery supplied by said hopper, said receptaclehaving a top including first valve means for selectably connecting saidreceptacle to vacuum or ambient air; b. means for drawing vacuum in saidreceptacle; c. conduit means for connecting said receptacle to a supplyof said granular material; d. second valve means for selectablypermitting material flow from said receptacle into said hopper; and e.means for temporally adjustably closing said first valve means tovacuum, and hence opening said first valve means to air, and openingsaid second valve means responsively to visually detected presence of asuitable amount of material in said receptacle.
 2. Apparatus of claim 1further comprising baffle means at an inlet to said receptacle fordirectionally deflecting flow of material into said receptacle from saidconduit means thereby reducing kinetic energy of said material. 3.Apparatus of claim 1 wherein said receptacle is cylindrical andtransparent.
 4. Apparatus of claim 3 wherein ends of said receptacle arecastings.
 5. Apparatus of claim 4 wherein said first and second valvemeans are within said castings.
 6. Apparatus for providing plastic resinmaterial to a plurality of loading hoppers and maintaining said materialin said hoppers at or above preselected levels preparatory to deliveryof said material therefrom for processing comprising:a. a plurality oftemporary material storage receptacles for receiving said plastic resinmaterial prior to processing thereof by machinery supplied by respectiveones of said hoppers; b. means for drawing vacuum in said receptacles;c. first valve means selectably connecting said receptacles with saidvacuum drawing means; d. conduit means for connecting said receptaclesto respective supplies of plastic resin material; e. second valve meansfor selectably permitting plastic resin material flow from saidreceptacles into associated hoppers; and f. manually adjustable shutofftime control means for closing said first and second valve means,thereby permitting air flow into respective receptacles responsively tovisually detected criteria respecting level of said plastic resinmaterial in said receptive receptacle.
 7. Apparatus of claim 6 whereinsaid first and second valve means are actuated by pneumaticpiston-cylinder combinations.
 8. Apparatus of claim 6 wherein at leastone of said second valve means is a slide gate valve.
 9. Apparatus ofclaim 6 wherein at least one of said second valve means is a flapmaintained closed by gravity.
 10. Apparatus of claim 6 furthercomprising baffle means within at least one of said proximate an inletto said receptacle within which said baffle means is disposed from saidconduit means for directionally plurally deflecting flow of airborneplastic resin material drawn into said receptacle within which saidbaffle means resides from said conduit means thereby dissipating kineticenergy of said moving airborne resin material.
 11. Apparatus of claim 10wherein said baffle includes a generally parallel piped-shaped housinginto which said material entrained in air enters.
 12. Apparatus of claim10 wherein said baffle consists of planar surfaces.
 13. Apparatus ofclaim 6 wherein at least one of said receptacles has a cast topincluding means for connecting said respective receptacle to vacuum orambient air by simultaneously opening a connection to one of said vacuumand said ambient air and closing a connection to the remaining one ofsaid vacuum and ambient air.
 14. Apparatus of claim 6 further comprisingmeans for connecting said conduit means for plastic resin materialsupply to said respective receptacle including a plate inclined at anangle to flow direction of material drawn to said respective receptaclefor downwardly deflecting flowing material entering said respectivereceptacle.
 15. A method for providing plastic resin material to aloading receptacle and periodically replenishing said receptacle withsaid material, comprising:a. drawing a vacuum within said receptaclethereby inducing plastic resin material flow from a plastic resinmaterial supply into said receptacle and marking the commencement ofsaid drawing as a vacuum drawing starting time; and b. stopping saidinduced plastic resin material flow into said receptacle and markingsaid stoppage as a vacuum drawing stopping time responsively tooptically detected sensed material level within said receptacle.
 16. Themethod of claim 15 further comprising repeatedly drawing said vacuum fora filling period defined by the difference between said starting andstopping times and adjusting said filling period if needed by changingsaid stopping time responsively to observation of a desired materiallevel in said receptacle.
 17. The method of claim 15 wherein changingsaid filling period responsively to observation of a desired materiallevel in said receptacle is performed by actuating a switch during saidfilling period and deactuating said switch to define a new stoppingtime.
 18. The method of claim 15 further comprising directionallydeflecting plastic material flowing into said receptacle upon entrythereinto, thereby reducing kinetic energy of said flowing material. 19.The method of claim 15 further comprising thrice directionallydeflecting said material as said material enters said receptacle.
 20. Amethod for providing plastic resin material to a plurality of loadingreceptacles and periodically replenishing said receptacles with saidmaterial, comprising:a. drawing vacuum within said receptacles seriallythereby inducing plastic resin material flow from a plastic resinmaterial supply into each of said receptacles in a selected sequence andmarking the commencement of said drawing for each of said receptacles asa vacuum drawing starting time for a receptacle of interest; and b.stopping flow of material into said receptacles and separately markingsaid stoppage as a vacuum drawing stopping time for each of saidreceptacles responsively to optically detected sensed material levelwithin each of said receptacles.
 21. The method of claim 20 furthercomprising serially repeatedly drawing said vacuum for each of saidreceptacles for a filling period defined by the difference between saidstarting and stopping times and adjusting said filling period separatelyfor each of said receptacles if needed by changing said stopping timeresponsively to observation of a desired material level in saidreceptacle.
 22. The method of claim 21 wherein changing said fillingperiod responsively to observation of a desired material level in aselected one of said receptacles is performed by actuating a switchduring said filling period and deactuating said switch to define a newstopping time for said selected receptacle.
 23. The method of claim 22wherein a single switch is used to define a new stopping time for all ofreceptacles, as needed.
 24. The method of claim 20 further comprisingthrice directionally deflecting said material as said material enterssaid receptacle.